Foreign Minister Julie Bishop said Australian consular staff in Istanbul had visited major hospitals and morgues but found no Australians among the 36 dead and dozens more injured.

She warned there were still a number of unidentified bodies and consular staff would continue to investigate.

A Turkish official said the vast majority of those killed in the blast were Turkish nationals, but foreigners were also among the dead.

Prime Minister Binali Yildirim has told reporters the three suicide bombers blew themselves up after opening fire, with preliminary findings pointing to Islamic State responsibility.

Ataturk is Turkey’s largest airport and a major transport hub for international travellers. Pictures posted on social media from the site showed wounded people lying on the ground inside and outside one of the terminal buildings.

#BREAKING: Picture of the aftermeth caused by terror attack at #Istanbul airport pic.twitter.com/T77gPfwO6p

— Amichai Stein (@AmichaiStein1) June 28, 2016

One attacker opened fire in the departures hall with an automatic rifle, sending passengers diving for cover and trying to flee, before all three blew themselves up in or around the arrivals hall a floor below, witnesses and officials said.

Crime scene investigators work next to a body after a suicide bomb attack at Ataturk Airport. Photo: SEDAT SUNA, EPA.

The attack on Europe’s third-busiest airport is one of the deadliest in a series of suicide bombings in Turkey, which is struggling to contain the spillover from neighbouring Syria’s civil war and battling an insurgency by Kurdish militants in its southeast.

Police fired shots to try to stop two of the attackers just before they reached a security checkpoint at the arrivals hall, but they detonated their explosives, a Turkish official said.

“It became clear with this incident again that terrorism is a global threat. This attack, targeting innocent people is a vile, planned terrorist act,” Prime Minister Yildirim told reporters at the airport.

“There is initial evidence that each of the three suicide bombers blew themselves up after opening fire,” he said, adding that they had come to the airport by taxi and that preliminary findings pointed to Islamic State responsibility.

The vast majority of those killed were Turkish nationals but foreigners were also among the dead, the official said.

“There was a huge explosion, extremely loud. The roof came down. Inside the airport it is terrible, you can’t recognise it, the damage is big,” said Ali Tekin, who was at the arrivals hall waiting for a guest when the attack took place.

A woman named Duygu, who was at passport control having just arrived from Germany, said she threw herself onto the floor with the sound of the explosion. Several witnesses also reported hearing gunfire shortly before the attacks.

“Everyone started running away. Everywhere was covered with blood and body parts. I saw bullet holes on the doors,” she said outside the airport.

Almost seven hours after the attack, which started around 9.50pm local time, no group had claimed responsibility.

The attack bore similarities to a suicide bombing by Islamic State militants at Brussels airport in March which killed 16 people. A coordinated attack also targeted a peak-hour metro train, killing a further 16 people in the Belgian capital.

Paul Roos, 77, described seeing one of the attackers “randomly shooting” in the departures hall.

“He was just firing at anyone coming in front of him. He was wearing all black. His face was not masked. I was 50 metres away from him,” said Roos, a South African returning to Cape Town with his wife after a holiday in southern Turkey.

“We ducked behind a counter but I stood up and watched him. Two explosions went off shortly after one another. By that time he had stopped shooting,” Roos told Reuters.

“He turned around and started coming towards us. He was holding his gun inside his jacket. He looked around anxiously to see if anyone was going to stop him and then went down the escalator … We heard some more gunfire and then another explosion, and then it was over.”

Turkey has suffered a spate of bombings this year, including two suicide attacks in tourist areas of Istanbul blamed on Islamic State, and two car bombings in the capital, Ankara, which were claimed by a Kurdish militant group.

-AAP / Reuters